Control of gripper carriage

Abstract

Tray sealing machine (1) comprising a sealing station (2) for sealing trays (3), a feed conveyor (4) for providing trays (3), a discharge conveyor (5) for transporting sealed trays (3), a gripper device (6) comprising a first gripper unit (7) configured to pick up trays (3) from the feed conveyor (4) and position them within the sealing station (2) for a sealing operation, and a second gripper unit (8) configured to pick up the trays (3) sealed by the sealing station (2) and position them on the discharge conveyor (5) for transport, wherein the first gripper unit (7) comprises a first carriage (9) and a first gripper (10) mounted thereon, and the second gripper unit (8) comprises a second carriage (11) and a second gripper (12) mounted thereon, and a lifting mechanism (13) for opening and closing the sealing station (2).and a control device (14) for controlling a movement of the first carriage (9) and the first gripper (10) and for controlling a movement of the second carriage (11) and the second gripper (12), wherein the control device (14) is configured to control, during the opening of the lifting mechanism (13), both a closing movement (S) of the second gripper (12) carried out transversely to the production direction (R) for picking up sealed trays (3) from the sealing station (2) and an adjustment movement (V) of the first carriage (9) carried out in the production direction (R) for feeding unsealed trays (3) into the sealing station (2) such that there is essentially a predetermined minimum distance (x) between the first and the second carriage (9, 11),when the closing movement (S) of the second gripper (12) is at least substantially completed. Furthermore, the invention relates to a method for controlling a gripper device (6) of a tray closing machine (1).

Description

[0001] The present invention relates to a tray sealing machine with a gripper device according to claim 1. The invention further relates to a method for controlling a gripper device of a tray sealing machine according to claim 12.

[0002] DE 10 2018 215 914 A1 discloses a packaging machine comprising a sealing station, a feeder, a discharge conveyor, a control system, and a gripper system. The gripper system includes a first and a second gripper, each movable along a transport direction. Each gripper, in turn, comprises at least two gripper arms that can move relative to each other to open and close the gripper. The first gripper is configured to move one or more packaging trays from the feeder to the sealing station, and the second gripper is configured to move one or more packaging trays from the sealing station to the discharge conveyor and place them thereon. The control system of the packaging machine is designed to move the first gripper independently of the second gripper.Furthermore, it is possible that the gripping and / or movement of the first and / or second gripper occurs, at least in phases, simultaneously with the opening and / or closing of the sealing station. Although the independent operation of the first and second gripper described here is advantageous, there is still sufficient potential for improvement regarding the removal of sealed trays from the sealing station and the transport of unsealed trays into the sealing station, in order to perform a tray change at the sealing station as quickly as possible.

[0003] DE 10 2019 206 345 A1 discloses a tray sealing machine with a gripper device comprising a first and second tray gripper. Trays provided by a feeding unit are picked up by the tray grippers and transported to a sealing station. The speed of the tray grippers in the production direction is variable, so that it is initially lower than the speed of a conveyor belt of the feeding unit and, as soon as the tray grippers are brought close enough together transversely to the production direction to securely pick up the trays, are accelerated to a speed in the production direction that is higher than the speed of the conveyor belt of the feeding unit.

[0004] The object of the invention is to provide a tray sealing machine with an increased cycle rate.

[0005] This problem is solved by means of a tray sealing machine according to claim 1. Furthermore, this problem is solved by means of a method for controlling a gripper device according to claim 12.

[0006] Advantageous further developments of the invention are given by the technical features of the dependent claims.

[0007] The tray sealing machine according to the invention comprises a sealing station for sealing trays, a feed conveyor for supplying trays, a discharge conveyor for transporting sealed trays, and a gripper device. The gripper device has a first gripper unit configured to pick up trays from the feed conveyor and position them within the sealing station for a sealing operation. Furthermore, the gripper device comprises a second gripper unit configured to pick up the trays sealed by the sealing station and position them on the discharge conveyor for transport. The first gripper unit has a first carriage and a first gripper mounted thereon, and the second gripper unit has a second carriage and a second gripper mounted thereon.Furthermore, the tray sealing machine includes a lifting mechanism for opening and closing the sealing station and a control device for controlling a movement of the first slide and the first gripper as well as for controlling a movement of the second slide and the second gripper.

[0008] According to the invention, the control device is configured to control, during the opening of the lifting mechanism, both a closing movement of the second gripper carried out transversely to the production direction for picking up sealed trays from the sealing station and an adjustment movement of the first carriage carried out in the production direction for feeding unsealed trays into the sealing station in such a way that there is essentially a predetermined minimum distance between the first and the second carriage when the closing movement of the second gripper is at least substantially completed.

[0009] In the invention, at least the closing movement of the second gripper, carried out transversely to the production direction, the adjustment movement of the first carriage, carried out in the production direction, and the opening of the sealing station can be coordinated and controlled by the control device in such a way that, at a point in time when the closing movement of the second gripper is at least substantially complete, the first carriage of the first gripper unit and the second carriage of the second gripper unit are moved substantially towards each other as closely as possible, i.e., the two carriages have a predetermined minimum distance from each other in the production direction. This ensures that when the sealed trays are picked up by the second gripper, i.e.,At a point when the trays are picked up by the second gripper, the first gripper unit is already positioned close to the sealing station to perform the tray change at the sealing station as quickly as possible. Consequently, the time the sealing station is open can be reduced, which improves the overall quality of the products being manufactured and also increases the machine throughput, i.e., the cycle time.

[0010] One variant provides that the control unit is designed to calculate the minimum distance between the first and second carriages from the respective travel curves it holds for the first carriage, the first gripper, the second carriage, and / or the second gripper. Based on this minimum distance, a start time can be determined for the respective travel curves of the first carriage, the first gripper, the second carriage, and / or the second gripper with respect to their predetermined initial positions. This sequence control ensures that the minimum distance is always present when the two gripper units at the sealing station are moving as close together as possible.

[0011] A sophisticated variant provides that the control device is configured to determine at least one set of possible travel curves for the first slide, the first gripper, the second slide and / or the second gripper with regard to a minimum distance, preferably selectable directly at the tray closing machine, which must be maintained as a safety distance between the first and the second slide, and which can be displayed to an operator for selection, for example on a display.

[0012] It is conceivable that the respective travel curves for the first carriage, the first gripper, the second carriage, and / or the second gripper per work cycle of the sealing station can be recorded, and that the control unit is designed to calculate the minimum distance between the first and second carriages from the respective recorded travel curves. Based on this minimum distance, a start time can be determined for the respective travel curves of the first carriage, the first gripper, the second carriage, and / or the second gripper with respect to their predetermined starting positions. This allows the cycle time of the tray sealing machine to be optimized with regard to the actually measured process.

[0013] Preferably, the control device is configured to control the closing movement of the second gripper and the adjustment movement of the first slide in the production direction such that the predetermined minimum distance between the first and second slides is maintained when the first slide is adjusted to its maximum extent in the production direction. In this variant, the second slide of the second gripper unit has already moved in the production direction from a certain area of ​​the sealing station further towards the discharge conveyor, while the first slide of the first gripper unit has moved fully into the area of ​​the sealing station to discharge the trays it has picked up.In other words, the first and second carriages are moved towards each other in such a way that the distance between them is progressively reduced as the second carriage moves out of the sealing station and as the first carriage moves into the sealing station, until the first carriage reaches its final position, which is accessible in the production direction. In terms of magnitude, the acceleration of the first carriage as it moves into the sealing station is therefore greater than the simultaneous acceleration of the second carriage as it moves out of the sealing station.Such a time-coordinated approach to the predetermined minimum distance between the first and second slides by means of the control device offers advantageous collision protection between the two gripper units, since, upon reaching the minimum distance described here at the time of a maximum adjustment movement of the first slide in the production direction, the second slide of the second gripper unit subsequently moves further away from it in order to transfer the sealed trays to the discharge conveyor.

[0014] One variant provides that the control unit is configured to control the closing movement of the second gripper and the adjustment movement of the first carriage in the production direction such that the predetermined minimum distance between the first and second carriages is maintained when the second carriage begins to move in the production direction. In this embodiment, the first gripper unit with the trays it holds is already positioned as close as possible to the sealing station, i.e., at the predetermined minimum distance to the second carriage, when the second carriage begins to move in the production direction to transport the sealed trays held by the second gripper out of the sealing station.In this variant, the predetermined minimum distance between the first and second carriages is thus established at a time when the second gripper unit has picked up the sealed trays for removal from the sealing station, but has not yet left the area of ​​the sealing station, while the first gripper unit has moved towards the sealing station, but has not yet entered the area of ​​the sealing station.

[0015] Preferably, the control device is designed to control the opening of the lifting mechanism, the closing movement of the second gripper, and the adjustment movement of the first slide in the production direction such that the predetermined minimum distance between the first and second slides is maintained when the second slide has reached its end position opposite the production direction. In this variant, the first and second slides move simultaneously towards each other to achieve the minimum distance until the second slide has reached its end position opposite the production direction. The first slide is then already moved towards the sealing station in the production direction, i.e., opposite to the movement of the second slide, to such an extent that the predetermined minimum distance between the two slides is maintained.This allows for further time optimization of the opening of the lifting mechanism, the collection of sealed trays and the handover of unsealed trays at the sealing station to achieve increased cycle rates.

[0016] Preferably, the control device is configured to control the closing movement of the second gripper and the adjustment movement of the first gripper in the production direction such that the first and second slides accelerate at least temporarily with opposite signs and the same magnitude when the second gripper is adjusted to its maximum transverse position to the production direction. This means that the first slide decelerates as it approaches the sealing station, while the second slide simultaneously accelerates out of the sealing station to clear the area within the sealing station for the transfer of unsealed trays by the first gripper unit.

[0017] Preferably, the control device is configured to control the adjustment movement of the first slide in the production direction such that the distance between the first and second slides can be changed. In other words, the respective adjustment movements of the first and second slides in the production direction can be controlled independently of each other.

[0018] According to one embodiment, the control device is designed to control the opening of the lifting mechanism, the closing movement of the second gripper, and the adjustment movement of the first carriage in the production direction such that the predetermined minimum distance between the first and second carriages is maintained when the lifting mechanism is fully open. Because the point in time at which the predetermined minimum distance between the first and second carriages is maintained coincides with the point in time at which the lifting mechanism is fully open to open the sealing station, optimal collision protection is achieved for the transfer of unsealed trays and the retrieval of sealed trays at the sealing station.

[0019] Preferably, the control unit is configured to determine a start time for the adjustment movement of the first slide in the production direction for each machine cycle, depending on the detected closing movement of the second gripper, the detected opening of the lifting mechanism, and / or a process parameter of the sealing station detected at the sealing station. This allows the movement of the first gripper unit to be optimized for each machine cycle, if necessary.

[0020] To detect the closing movement of the second gripper, the opening of the lifting mechanism, and / or the process parameter of the sealing station, at least one sensor unit, such as a camera, can be provided at the sealing station. Depending on the measurements taken, the control unit can determine and control, in particular, the starting point for the adjustment movement of the first carriage in the production direction. This allows the first carriage to start moving early enough, based on the process progress measured at the sealing station, to reach the predetermined minimum distance by the time the closing movement of the second carriage is at least substantially complete.

[0021] One variant involves configuring the control unit to determine, based on a predefined speed profile of the second slide and / or gripper (defined as a guide logic), a dependent speed profile of the first slide and / or gripper (defined as a follower logic). The respective speed profiles can then be combined by the control unit in such a way that the predetermined minimum distance between the first and second slides is achieved when the closing movement of the second gripper is at least substantially complete.

[0022] An advantageous variant provides that the control unit is configured to determine, based on a speed profile of the second slide and / or the second gripper measured as a guide logic, a dependent speed profile of the first slide and / or the second gripper, generated as a follower logic. The respective speed profiles can be calculated with each other by the control unit in such a way that the predetermined minimum distance between the first and the second slide is reached when the closing movement of the second gripper is at least substantially complete.

[0023] One embodiment of the invention provides that the control unit is configured to determine the minimum distance based on a desired tray changeover time adjustable on the tray sealing machine and to control the movements of the first and second gripper units accordingly. Using the variably adjustable tray changeover time, it is possible to better coordinate the operation of the sealing station and the gripper unit with other work units of the tray sealing machine and / or with other work units cooperating with the tray sealing machine.

[0024] It is possible that the control device includes a distance control control, wherein the first and / or the second gripper unit has at least one measuring unit for detecting a distance between the first and the second slide, wherein an acceleration of the first slide in the production direction during the closing movement of the second gripper can be controlled depending on the detected distance.

[0025] The invention further relates to a method for controlling a gripper device of a tray sealing machine, wherein a first gripper unit picks up trays from a feed belt by means of a first gripper formed thereon and transports them into a sealing station of the tray sealing machine for a sealing process, and wherein a second gripper unit positioned downstream of the first gripper unit in the production direction picks up the trays sealed within the sealing station by means of a second gripper formed thereon and positions them on a discharge belt for removal.

[0026] The invention provides that a control device of the tray sealing machine, during the opening of the sealing station, controls both a closing movement of the second gripper carried out transversely to the production direction for picking up sealed trays from the sealing station, and an adjustment movement of a first slide of the first gripper unit carried out in the production direction for feeding unsealed trays into the sealing station, such that there is essentially a predetermined minimum distance between the first slide of the first gripper unit and a second slide of the second gripper unit in the production direction when the closing movement of the second gripper is essentially completed.

[0027] In the invention, during the opening of the sealing station, a closing movement of the second gripper transverse to the production direction occurs in conjunction with an adjustment movement of the first carriage in the production direction. These movements are coordinated in such a way that the first and second gripper units have moved towards each other as close as possible for a tray change, thus shortening the tray change time—that is, the time required to pick up sealed trays from the sealing station and to deliver unsealed trays to the sealing station. This shortened tray change time allows the sealing station to close again as quickly as possible in order to seal the trays picked up by the first gripper unit.

[0028] Advantageous embodiments of the invention are explained in more detail with reference to the following figures. Fig. 1 a schematic representation of a tray closing machine according to the invention, Fig. 2A a snapshot of a gripper device for approaching a predetermined minimum distance, Fig. 2A a further snapshot of the gripper device for approaching a predetermined minimum distance, Fig. 3A - 3A a schematic representation of adjustment movements of the gripper device, Fig. 4A - 4A a further schematic representation of adjustment movements of the gripper device, and Fig. 5A - 5C a further representation of adjustment movements of the gripper device.

[0029] Identical components are consistently labelled with the same reference symbols in the figures.

[0030] Fig. 1 Figure 1 shows a schematic representation of a tray sealing machine 1. Such a tray sealing machine 1 is also known as a tray sealer in technical circles. The tray sealing machine 1 comprises a sealing station 2 for sealing trays 3. Furthermore, the tray sealing machine 1 has a feed conveyor 4 for supplying trays 3 and a discharge conveyor 5 for transporting sealed trays 3.

[0031] The in Fig. 1 The tray sealing machine 1 shown comprises a gripper unit 6 with a first gripper unit 7 and a second gripper unit 8. The first gripper unit 7 is configured to pick up unsealed trays 3 from the feed conveyor 4 and position them within the sealing station 2 for sealing. The second gripper unit 8 is configured to pick up the trays 3 sealed by the sealing station 2 and position them on the discharge conveyor 5 for removal. The first gripper unit 7 has a first carriage 9 and a first gripper 10 adjustable to it. The second gripper unit 8 has a second carriage 11 and a second gripper 12 adjustable to it.

[0032] The tray sealing machine 1 from Fig. 1 It also has a lifting mechanism 13 for opening and closing the sealing station 2. Furthermore, it shows Fig. 1 A control device 14 for controlling the movement of the first carriage 9 and the first gripper 10, as well as for controlling the movement of the second carriage 11 and the second gripper 12. The control device 14 is functionally connected to a first drive 15 of the first gripper unit 7 and functionally to a second drive 16 of the second gripper unit 8. The control device 14 is configured to control the first and second drives 15, 16 independently of each other. In particular, the control device can be configured to control the respective carriages 9, 11 of the first and second gripper units 7, 8 such that they move towards or away from each other while the sealing station 2 is supplied with trays 3 or sealed trays 3 are transported out of it.

[0033] For a sealing operation, the tray closing machine 1 has a lower tool part 17 and an upper tool part 18 arranged above it. The lower tool part 17 is designed according to Fig. 1 The lower tool part 17 is mounted in a height-adjustable manner by means of the lifting mechanism 13. The height adjustability of the lower tool part 17 is shown by the double arrow 19. For the sealing process, the lower tool part 17 can be raised against the upper tool part 18 positioned above it in order to seal the trays 3 placed on the lower tool part 17 with a top film 20 passed through the sealing station 2. According to Fig.1 A sensor unit 21 is provided at the sealing station 2, which is designed to record at least one process parameter during the sealing process at the sealing station 2.

[0034] According to Fig. 1 A measuring unit 22 is provided on the first slide 9 of the first gripper unit 7, which is designed to detect a distance between the first and the second slide 9, 11. This distance can be transmitted to a distance control controller 23 of the control unit 14, on the basis of which the control unit 14 controls a closing movement and / or an adjustment movement of the first and / or second gripper unit 7, 8.

[0035] Furthermore, it shows Fig. 1 The control unit 14 can be given a desired tray change time t, based on which the control unit 14 can determine a minimum distance x between the first and second slides 9, 11. Based on the predetermined minimum distance x, the first and second gripper units 7, 8 can be moved into and out of the sealing station 2 for a tray change.

[0036] The respective slides 9, 11 of the first and second gripper units 7, 8 can be adjusted along a guide 24 in the production direction R. Fig. 1 shows that the first gripper unit 7 transports trays 3 from the feed belt 4 into the sealing station 2 in the production direction R, and the second gripper unit 8 transports sealed trays 3 out of the sealing station 2 and hands them over to the discharge belt 5.

[0037] The in Fig. 1 The control device 14 shown is configured to perform a closing movement S transverse to the production direction R during the opening of the lifting mechanism 13, i.e. during the opening of the sealing station 2 (see Figur 3A ) of the second gripper 12 for picking up sealed trays 3 from the sealing station 2, as well as an adjustment movement V of the first slide 9 carried out in the production direction R for feeding unsealed trays 3 into the sealing station 2, such that the predetermined minimum distance x (see Figur 3B ) exists when the closing movement S of the second gripper 12 is at least substantially completed.

[0038] The closing movement S and the adjusting movement V can be controlled differently by means of the control device 14 according to the following embodiments.

[0039] Fig. 2A Figure 1 shows a variant in which the control unit 14 controls the closing movement S of the second gripper 12 and the adjustment movement V of the first slide 9 in the production direction R such that the predetermined minimum distance x between the first and second slides 9, 11 is maintained when the first slide 9 is adjusted to its maximum extent in the production direction R. At this point, the second gripper 12 has already left the sealing station 2 to position the sealed trays 3 it has picked up on the discharge conveyor 5. Fig. 2A The minimum distance x between the first and second slides 9, 11 is reached when the first slide 9 is adjusted to its maximum extent in the production direction R, i.e., the first gripper 10 is opened to transfer the trays 3 picked up by it to the lower part 17 of the sealing station 3.

[0040] Fig. 2B Figure 1 shows a variant in which the control unit 14 is configured to control the closing movement S of the second gripper 12 and the adjustment movement V of the first slide 9 in the production direction R such that the predetermined minimum distance x between the first and second slides 9, 11 is maintained when the second slide 11 begins to move in the production direction R. In this variant, the minimum distance x between the first and second slides 9, 11 is reached when the sealed trays 3 have been picked up by the second gripper unit 8 and the first gripper unit 7 has moved as close as possible to the sealing station 2, but has not yet entered it. In contrast to the Fig. 2A is therefore according to Fig. 2B The minimum distance x has already been reached before the first carriage 9 has reached its final position in the production direction R.

[0041] The Figuren 3A bis 3D show a movement of the gripper device 6 for transporting trays along the tray sealing machine 1.

[0042] Fig. 3A Figure 1 shows the gripper device 6 in an initial position. In this position, during the opening of the lifting mechanism 13, both a closing movement S of the second gripper 12, carried out transversely to the production direction R, to pick up sealed trays 3 from the sealing station 2, and an adjustment movement V of the first carriage 9, carried out in the production direction R, to feed unsealed trays 3 into the sealing station 2. The closing movement S and the adjustment movement V are controlled by the control device 14 such that a predetermined minimum distance x exists between the first and the second carriage 9, 11 when the closing movement S of the second gripper 12 is at least substantially completed. This shows Fig. 3B .

[0043] According to Fig. 3C The sealed trays 3 picked up by the second gripper unit 8 are transported in production direction R to the discharge conveyor 5. Simultaneously, the unsealed trays 3 picked up by the first gripper unit 7 are transported into the sealing station 2. At this point, the two carriages 9 and 11 can already move apart again.

[0044] Fig. 3D This shows that by opening the second gripper unit 12, the sealed trays 3 picked up by it are transferred to the discharge conveyor 5. Simultaneously or at a later time, the first gripper unit 7 transfers the unsealed trays 3 picked up by the first gripper 10 to the sealing station 2 for the sealing process.

[0045] The Fig. 3A bis 3D show that the minimum distance x between the first and second slides 9, 11 is essentially present when the sealed trays are picked up by the second gripper 12 and the first gripper 10 has moved to its maximum extent to the open sealing station 2.

[0046] The Fig. 4A bis 4D show an alternative movement of the gripper device 6 for transporting trays 3 along the tray sealing machine 1.

[0047] According to Fig. 4A The initial situation is such that the closing movement S of the second gripper 12 begins. Simultaneously or with a time delay, the first slide 9 of the first gripper unit 7 starts with an adjustment movement V in the production direction R.

[0048] Fig. 4B This shows that the first gripper unit 7 has moved further in the production direction R towards the sealing station 2. The trays sealed in the sealing station 2 are picked up by the second gripper unit 8 in order to be transported out of the sealing station 2.

[0049] Fig. 4C This shows the time at which the predetermined minimum distance x between the first sled 9 and the second sled 11 is reached. According to Fig. 4C This refers to the point in time at which the first carriage 9 is maximally adjusted in the production direction R. At this point, the second gripper 12 has already left the sealing station 2.

[0050] The Fig. 4D The diagram shows the opening of the two grippers 10 and 12 to transfer the trays to the sealing station 2 and the sealed trays 3 to the conveyor belt 5. The opening of the two grippers 10 and 12 can be coordinated and performed simultaneously.

[0051] The Fig. 3B and 4C Figure 1 shows various ways in which the control unit 14 can control the minimum distance x between the first slide 9 and the second slide 11. According to Fig. 3B The minimum distance x is reached when the second carriage 11 begins to move in the production direction R. According to Fig. 4C The minimum distance x is present when the first carriage 9 is adjusted to the maximum extent in the production direction R.

[0052] The Fig. 5A bis 5C Figure 1 shows another variant of how the movement of the gripper device 6 can be controlled by means of the control device 14 in order to maintain a minimum distance x between the first slide 9 and the second slide 11. Fig. 5A Figure 1 shows an initial situation in which the second gripper unit 8 is adjusted both against and perpendicular to the production direction R. Based on this adjustment and simultaneous closing movement, it is possible that the second gripper 12 already performs a closing movement S perpendicular to the production direction R while the second slide 11 is adjusting against the production direction R (see Figure 1). Fig. 5B The control device 14 can control the opening of the lifting mechanism 13, the closing movement S of the second gripper 12, and the adjustment movement of the second slide 11 against the production direction R in such a way that the predetermined minimum distance x between the first and the second slide 9, 11 is maintained when the second slide 11 is in an end position against the production direction R according to Fig. 5C has arrived. At this point, the first sled 9 has already moved close enough to the sealing station 2 that the predetermined minimum distance x between the first and the second sled 9, 11 is established. From the initial situation in Fig. 5A The retraction of the first gripper unit 7 shown, analogous to the movement of the second gripper unit 8, can also take place simultaneously against the production direction R and perpendicular to the production direction R in order to pick up the trays 3 provided on the feed belt 4.

Claims

1. Tray sealer (1), comprising a sealing station (2) for sealing trays (3), an infeed belt (4) for providing trays (3), an outfeed belt (5) for transporting sealed trays (3) away, a gripper device (6) comprising a first gripper unit (7) which is configured to pick up trays (3) from said infeed belt (4) and to position them for a sealing process within said sealing station (2), and comprising a second gripper unit (8) which is configured to collect trays (3) sealed by way of said sealing station (2) and to position them on said outfeed belt (5) for being transported away, where said first gripper unit (7) comprises a first carriage (9) as well as a first gripper (10) mounted thereon and said second gripper unit (8) comprises a second carriage (11) and a second gripper (12) mounted thereon, a lifting mechanism (13) for opening and closing said sealing station (2), as well as a control device (14) for controlling a motion of said first carriage (9) and said first gripper (10) as well as for controlling a motion of said second carriage (11) and said second gripper (12), characterized in that, during the opening of said lifting mechanism (13), said control device (14) is configured to control a closing motion (S) of said second gripper (12) carried out transverse to said direction of production (R) for collecting sealed trays (3) from said sealing station (2) as well as an adjusting motion (V) of said first carriage ( 9) carried out in said direction of production (R) for supplying unsealed trays (3) into said sealing station (2) such that a substantially predetermined minimum distance (x) is present between said first and said second carriage (9, 11) when said closing motion (S) of said second gripper (12) is at least substantially completed.

2. Tray sealer according to claim 1, characterized in that said control device (14) is configured to control said closing motion (S) of said second gripper (12) and said adjusting motion (V) of said first carriage (9) carried out in said direction of production (R) such that that said predetermined minimum distance (x) is present between said first and said second carriage (9, 11) when said first carriage (9) is adjusted to the maximum in said direction of production (R).

3. Tray sealer according to claim 1, characterized in that said control device (14) is configured to control said closing motion (S) of said second gripper (12) and said adjusting motion (V) of said first carriage (9) carried out in said direction of production (R) such that that said predetermined minimum distance (x) is present between said first and said second carriage (11) when said second carriage (9) begins to move in said direction of production (R).

4. Tray sealer according to one of the preceding claims, characterized in that said control device (14) is configured to control the opening of said lifting mechanism (13), said closing motion (S) of said second gripper (12), and said adjusting motion (V) of said first carriage (9) carried out in said direction of production (R) such that that said predetermined minimum distance (x) is present between said first and said second carriage (9, 11) when said second carriage (11) has arrived at an end position (E) in a direction opposite to said direction of production (R).

5. Tray sealer according to one of the preceding claims, characterized in that said control device (14) is configured to control said closing motion (S) of said second gripper (12) and said adjusting motion (V) of said first carriage (9) carried out in said direction of production (R) such that that said first and said second carriage (9, 11) accelerate at least temporarily at the same magnitude with opposite signs when said second gripper (12) is adjusted to the maximum transverse to said direction of production (R).

6. Tray sealer according to one of the preceding claims, characterized in that said control device (14) is configured to control said adjusting motion (V) of said first carriage (9) carried out in said direction of production (R) such that a distance between said first and said second carriage (9, 11) can be changed.

7. Tray sealer according to one of the preceding claims, characterized in that said control device (14) is configured to control the opening of said lifting mechanism (13), said closing motion (S) of said second gripper (12), and said adjusting motion (V) of said first carriage (9) carried out in said direction of production (R) such that that said predetermined minimum distance (x) is present between said first and said second carriage (11) when said lifting mechanism (13) is open to the maximum.

8. Tray sealer according to one of the preceding claims, characterized in that said control device (14) is configured to set a starting time for said adjusting motion (V) of said first carriage (9) carried out in said direction of production (R) per machine work cycle in dependence of said detected closing motion (S) of said second gripper (12), in dependence of said detected opening of said lifting mechanism (13) and / or in dependence of a process parameter of said sealing station (2) detected at said sealing station (2).

9. Tray sealer according to one of the preceding claims, characterized in that said control device (14) is configured to determine, on the basis of a speed profile of said second carriage (11) and / or said second gripper (12) predetermined as a guide logic, a speed profile dependent thereon of said first carriage (9) and / or said second gripper (10) formed as an inference logic.

10. Tray sealer according to one of the preceding claims, characterized in that said control device (14) is configured to determine said minimum distance (x) on the basis of a desired tray exchange time (t) that can be adjusted at said tray sealer (1) and to control in dependence thereof the motions of said first and said second gripper unit (7, 8).

11. Tray sealer according to one of the preceding claims, characterized in that said control device (14) comprises a distance control device (23), where said first and / or said second gripper unit (7, 8) comprises at least one measuring unit (22) for detecting a distance between said first and said second carriage (9, 11), where an acceleration of said first carriage (9) in said direction of production (R) during said closing motion (S) of said second gripper (12) can be controlled in dependence of the distance detected.

12. Method for controlling a gripper device (6) of a tray sealer (1), where a first gripper unit (7) by way of a first gripper (10) formed thereon picks up trays (3) from an infeed belt (4) and transports them into a sealing station (2) of said tray sealer (1) for a sealing process, and where a second gripper unit (8) positioned in said direction of production (R) downstream of said first gripper unit (7) by way of a second gripper (12) formed thereon collects said trays (3) sealed within said sealing station (2) and positions them on an outfeed belt (5) for being transported away, characterized in that, during the opening of said lifting mechanism (13), said control device (14) is configured to control a closing motion (S) of said second gripper (12) carried out transverse to said direction of production (R) for collecting sealed trays (3) from said sealing station (2) as well as an adjusting motion (V) of said first carriage (9) of said gripper unit (7) carried out in said direction of production (R) for supplying unsealed trays (3) into said sealing station (2) such that a substantially predetermined minimum distance (x) is present between said first carriage (9) of said first gripper unit (7) and a second carriage (11) of said second gripper unit (8) when said closing motion (S) of said second gripper (12) is at least substantially completed.

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